For a band whose lyrics were famously difficult to make out most of the time, the Cocteau Twins left an indelible impact on the world of pop music.

The Scottish trio emerged in the 1980s as some of the most notable pioneers of dream pop, a subgenre of alternative rock defined by airy, sublime sonic textures. But it was their sixth album, Heaven or Las Vegas—which turns 30 today—that truly withstood the test of time, affirming the Cocteau Twins' status as perhaps the most important dream pop act of all time.